Refrigerator gas liquification device



REFRIGERATOR GAS LIQUIFICATION DEVICE Filed May 1, 1952 Jacob Willem cu?KgPer y W AGE/VT Unitlid tates Pat REFRIGERATOR GAS LIQUIFICATION DEVICEJacob Willem Laurens Kiihler, Eindhoven, Netherlands,

assignor to Hartford National Bank and Trust Company, Hartford, Conn.,as trustee Application May 1, 1952, Serial No. 285,439 Claims priority,application Netherlands May 25, 1951 5 Claims. (Cl. 62-122) Thisinvention relates to refrigerators of the type comprising two spaceswhich vary in volume continuously and with a substantially constantrelative phase difference, one of the spaces having a lower temperatureand the other a higher temperature, said spaces communicating with eachother by way of a freezer, a regenerator and a cooler, and containing agas of invariable chemical composition which traverses a closedthermodynamic cycle whilst being in the same physical state. Suchrefrigerators are known and are often referred to as refrigeratorsoperating on the reversed hot-gas engine principle.

It has been suggested before by the applicant to construct such arefrigerator so as to be adapted to cool a gaseous medium, for exampleair, to at least -l50 C., this temperature being reached in one stage bythe process which takes place in the refrigerator machine.

The present invention relates to cold gas refrigerators of the typedefined above, for condensing gas and which for this purpose isconstructed so as to enable the condensed medium to be collected in asimple manner. In addition, the medium to be condensed is not compressedprior to the condensation proper, as is the case with'known gascondensing systems. This enables the refrigerator according to theinvention to be constructed in a considerably simpler manner than thesaid known systems.

According to the invention, a refrigerator comprising two spaces whichvary in volume continuously and with substantially constant relativephase difference, one of the spaces having a lower temperature and theother a higher temperature, said spaces communicating one with the otherby way of a freezer, a regenerator, and a cooler and con taining a gasof invariable chemical composition which traverses a closedthermo-dynamic cycle whilst being in the same physical state, ischaracterized in that thi's'machine is adapted to condense a gaseousmedium, for example air, at at least 150 0, this temperature beingreached in one stage by the process which takes place in therefrigerator, and the medium to be condensed enters into direct contactwith a wall of the freezer through which heat exchange with the workingmedium of the machine is effected, and condenses on said wall, the gaspressure of the medium to be condensed being near this wallsubstantially equal to atmospheric pressure and the freezer beingconstructed so as to enable the condensed medium to drip down and to becollected in a collector arranged at the lower end of the freezer.

It has been found that if the distance of the liquid level in therecipient from the lower end of that wall part of the freezer which isin heat-exchanging contact with the working medium in the machine iscomparatively large, that part of the freezer which is adjacent theregenerator may assume an excessively low temperature due to the factthat the heat-transmission from this part is insufiicient. This alsocauses the temperature of the colder end face of the regenerator to beexcessively low so that the temperature gradient across the regeneratoris unnecessarily large with the result that the efficiency of themachine is lowcred.

A further disadvantage is that the surface of the freezer on which themedium condenses becomes excessively small.

According to a preferred embodiment of the invention, in which thefreezer is arranged vertically, the freezer, therefore, comprises at itslower end an annular collector for the condensed medium, said collectorbeing constructed so that the vertical distance of the liquid level inthis collector from the lower end of that wall part of the freezer whichis in heat-exchanging contact with the Working medium in therefrigerator does not exceed one third part, and preferably does notexceed one sixth part of the height of this Wall part.

It is also desirable that the collector should not extend over a largepart of the height of the regenerator. As a rule, the regenerator willbe surrounded by an insulating layer, but it has been found that forstructural reasons the insulating layer between the collector and theregenerator cannot be thick. Thus, heat exchange is liable to occurbetween the collector and the regenerator. This heat exchange mayadversely affect the efficiency of the regenerator. It is thereforepreferred that in a refrigerator in which the freezer is arrangedvertically, the collector is provided at its lower end with an annularcollector for the condensed medium, which is constructed so that thebottom of this collector is located, at a maximum at a third,preferably, at a maximum, at a sixth of the height of the regeneratorbelow the colder end face of the regen erator.

If condensing media which contain gases or vapours having a higherfreezing point than the condensing point of the medium required to becondensed, solid is liable to form on the freezer. This solid, forexample ice, may find its Way into the collector. If no particularmeasures were taken, the solid could not be carried along with theliquid medium and would remain in the collector thus giving rise toclogging of the collector. In order that said solid may as far aspossible be carried along with the condensed liquid, the collector maycomprise a discharge pipe for the condensed medium, which at a shortdistance above the bottom of the collector leads out from the collectorin a manner such that when the machine is in use said bottom is coveredthroughout its surface with a layeL of liquid medium.

If the refrigerator, after having operated, is stopped, some solid mayremain in the collector, so that liquid is formed in the collector onrise of temperature of the freezer and collector. On the refrigeratorbeing re-started, this liquid is reconverted into solid and this soliddeposit may affect adversely the discharge of condensed medium. In orderto avoid the presence ofsuch liquid in the recipient on the refrigeratorbeing put into use provision may be made, at the lowest point of therecipient, of an aperture adapted tobe closed.

It may be desirable that the cold gas refrigerator should supply twodifferent media of low temperature having a different temperature andbeing adapted to be employed for different uses. At the freezer, thesedifferent media may differ either both in physical state and intemperature or in temperature alone.

It may be desirable, for example, that the refrigerator should supplynot only liquid air at, say, C., but also air in a gaseous state and ata higher temperature, for example at -l50 C. Provision may therefore bemade of a discharge channel connected to the collector above the liquidlevel of said collector and used for the purpose of discharging gaseousmedium available above this liquid level.

The invention will now be described with reference to the accompanyingdiagrammatic drawing, given by way of example, in which Fig. 1 shows avertically-arranged refrigerator according to the invention,

Fig. 2 shows part of a refrigerator, being a modification of that shownin Fig. 1 and Fig. 3 shows a horizontally-arranged refrigeratoraccording to the invention.

The refrigerator shown in Fig. 1 comprises a cylinder 1 in which adisplacer 2 and a piston 3 are adapted to reciprocate. The displacer 2and the piston 3 are connected to a crank shaft 6 by driving rodmechanisms 4 and 5, respectively. The space 7 above the displacer 2 isthe freezing space of the machine and communicates via a freezer S,regenerator 9 and cooler 10 with a space 11 between the displacer andthe piston, said space being referred to as the cooled space. The cranksof the machine are at an angle of 90 and the sense of rotation of thecrank shaft is such that the volume variation of the freezing space 7leads in phase relative to cooled space 11. The refrigerator is drivenby means of an electric motor 12 indicated by broken lines. The freezer8 comprises at its lower end a collector 13, constructed as an annularchannel, for receiving condensed medium. A discharge pipe 14 leads outfrom the collector 13. The maximum height a of the liquid level 15 isone third of the height b of fins 16 of the freezer 8. The collector 13comprises in addition a discharge pipe 17 which may be closed by meansof a tap 18 and through which, when the machine is being put into use,any Water present in the annular channel can be drained. The collector13 also comprises a discharge pipe 19 for the discharge of cooled gasavailable in the collector 13 above the liquid level. The Wall of thefreezer 8 is externally provided with fins 20.

The refrigerator operates as follows. On the machine being put into usethe temperature of the freezer falls to, say, -l98 C. The medium to becondensed, for example air, enters into direct contact with the fins 2t)and with the wall of the freezer 8, through which wall heat exchangetakes place, and condenses both on the fins 20 and on the wall 8. Thegas pressure of the medium to be condensed near the wall issubstantially equal to atmospheric pressure. The liquid produced iscollected in the collector 13. The discharge pipe 14 is arranged at asmall distance above the bottom of the annular channel of the collector13 so that any particles of ice that may be present can be carried alongwith the liquid produced and accumulation of ice particles is prevented.Arranged above the liquid level 15 is the discharge pipe 19 by means ofwhich cold gas above the liquid level can be drawn 01f so as to enablethe refrigerator to be used for two purposes, namely the supply ofcondensed liquid and the supply of gas at a low temperature.

The refrigerator shown in Fig. 2 the upper part of which is only shown,comprises a collector 31 of construction slightly different from thecollector 13 shown in Fig. 1. The collector 31 is arranged in a mannersuch that invariably the entire wall surface of the freezer can be usedfor condensation. However, the lower part 32 of the collector 31 isarranged, at a maximum of a third and preferably at a maximum of a sixthof the height of the regenerator 9 below the cold end face of theregenerator. The collector 31 may comprise discharge pipes similar tothose shown at 14, 17 and 19 in Fig. l which, however, for the sake ofsimplicity are not shown in this figure.

The horizontal refrigerator shown in Fig. 3 is constructed similarly tothose shown in Figs. 1 and 2, like parts being designated by the samereference numerals. In this embodiment, the freezer wall 8 is providedexternally with fins 40 vertically, so that condensed medium can dripdown from the fins 40. Arranged below the freezer is a collector 41 inwhich condensed medium can be collected. Condensed medium can bedischarged via the discharge pipe 42.

What I claim is:

1. A refrigerator comprising a freezer; a regenerator; a cooler; and twospaces containing a working medium of invariable chemical compositionwhich traverses a closed thermodynamic cycle while being in the samephysical state through said freezer, regenerator and cooler; one spacehaving a relatively lower temperature than the other space; the workingmedium in each of said spaces varying continuously in volume with asubstantially constant relative phase difference; a gaseous mediumsurrounding said freezer being adapted to condense at least at 15() C.on the outside wall of said freezer; the gas pressure of the medium tobe condensed being substantially equal to atmospheric pressure; anannular collector positioned at the end of said freezer adjacent to saidregenerator so that condensed medium may be collected in said collector;said collector being so constructed that the vertical height of theliquid level in said collector does not exceed one third of the heightof the wall of said freezer.

2. A refrigerator as set forth in claim 1 wherein the bottom of saidcollector is located a distance below the colder end of said regeneratora maximum of one third the total length of said regenerator.

3. A refrigerator as set forth in claim 1 further comprising a dischargepipe communicating with said collector at a certain distance above thebottom of said collector so that when said refrigerator is operating thebottom of said collector is continually covered with condensed medium.

4. A refrigerator as set forth in claim 1 further comprising a closeableoutlet in the bottom of said collector.

5. A refrigerator as set forth-in claim 1 further comprising a dischargeconduit communicating with said collector above the liquid level of saidcollector thereby affording the gaseous medium above said liquid level ameans for discharge.

References Cited in the file of this patent UNITED STATES PATENTS1,149,588 Lovekin Aug. 10, 1915 1,534,794 Lundgaard Apr. 21, 19251,553,546 Lundgaard Sept. 15, 1925 2,011,964 Ajam Aug. 20, 19352,468,293 DuPre Apr. 26, 1949 2,484,392 Van Heeckeren Oct. 11, 19492,590,519 DuPre Mar. 25, 1952 FOREIGN PATENTS 8,374 Great Britain June1, 1895

